1. Field of the Invention
The present invention relates to a receiving apparatus, and particularly to an apparatus for receiving a streaming broadcast.
2. Related Background Art
In recent years, information is distributed to individual households through various media. For example, television broadcasts, radio broadcasts, data broadcasts, etc. are distributed by means of ground waves as broadcast waves, satellites, etc. In addition, distribution services for images, audio, information, etc. are provided by means of the Internet, electronic mails, etc. through communication lines.
A conventional broadcast system is currently being shifted to a digital broadcast system in which television signals are transmitted as digital signals. The shift to the digital broadcast system is underway to enhance image quality and to increase the number of channels by utilizing digital transmission and coding technologies.
On the other hand, a communication system is benefiting from recent progresses of the digital coding technologies related to image and audio data, and from improved network environments (including broadband). As a result, it is becoming widespread to use the Internet to provide a distribution of moving images comparable in quality to that of the television broadcast, that is, a distribution of streaming contents (hereinafter, referred to as “streaming broadcast”).
The streaming broadcast includes the term “broadcast”, but is largely different in arrangement from the conventional television broadcast (of a push type) in the first place. In other words, while the distribution of the images and audio is similarly performed by means of the communication lines such as the Internet through, the streaming broadcast requires a user to access and obtain desired streaming contents (which is called a pull type). Unlike general television broadcast receiving, the streaming broadcast is not received immediately after calling up a desired channel.
Currently, the streaming broadcast is received (utilized) using a personal computer (hereinafter, referred to as “PC”) in most cases, and generally requires the following procedure.
A user who wishes to audiovisually enjoy the streaming broadcast must first find out desired contents (a desired streaming broadcast program) from among many streaming contents scattered throughout the Internet. For that purpose, the user activates an Internet browser, and then visits a portal site related to the streaming broadcast or searches through Websites by using a search engine or the like. Thus, the user finds out information on the desired streaming contents.
By the above operations, the user obtains information related to the desired streaming contents including program information such as a title, distribution information such as a start time, and address information such as a Uniform Resource Locator (hereinafter, referred to as “URL”). After that, the user accesses an address (URL) where the streaming contents exist to start to obtain the streaming contents. Concurrently, application software called a streaming player is activated, so that the streaming contents are audiovisually enjoyed (reproduced).
In the case of receiving the streaming contents, it is necessary to subject several to ten and several seconds of data to a buffering process before starting reproduction. The buffering process is performed as a requirement for decoding receive data on a terminal side, but mostly for mainly compensating uncertainty of speed on the Internet as a channel to perform smooth reproduction on the terminal side.
The above-mentioned type of receiving process for streaming contents is disclosed, for example, in JP 2001-359073 A.
As described above, the streaming broadcast is currently utilized by PC users in most cases. However, the present inventors presupposes that in the near future, while communication infrastructures are improved in the individual households, it becomes widespread to enjoy the streaming broadcast, as well as the conventional television broadcast, on television in living rooms.
In the above case, it is conceivable that it is demanded for a user to select and audiovisually enjoy a program (contents) of the streaming broadcast in such a manner as to feel as comfortable as in the conventional television broadcast.
The above-mentioned operation for audiovisually enjoying the streaming broadcast using a PC is the same as a conventional pull-type operation for obtaining information based on a demand (an instruction) of a user, such as an operation for browsing Websites or using electric mails. Therefore, a general PC user may feel no discomfort except that it is inconvenient to search for and audiovisually enjoy the streaming contents.
However, a general television audience is accustomed to watching television, that is, being able to audiovisually enjoy a desired program immediately after turning on a power and selecting a corresponding channel. Therefore, it is impractical for the television audience himself/herself to find out main data and a location (address (and a file name)) of streaming contents that he/she wishes to audiovisually enjoy, and to perform the pull-type operation for receiving distributed contents based on the found data. Thus, it is necessary to provide a form capable of selecting and audiovisually enjoying contents by a simpler method such that the audience feels as comfortable as when audiovisually enjoying a television program.
There is another problem described above in that unlike the general process for receiving the television broadcast, the receiving process for the streaming contents requires a time period of several to ten and several seconds at the time of switching the streaming contents which corresponds to the time of changing channels on television. Meanwhile, the user must wait for the same time period.
The above problem is caused by the time period for buffering described above, which equals to a total length of a time period required for buffering desired streaming contents in a distribution side server and a time period required for buffering a predetermined amount of the streaming contents on a receiving terminal side. Generally, the higher a data rate for contents is, the longer the buffering time period for the contents becomes.
Accordingly, it is impossible that the user selects the desired streaming contents in such a manner as to feel as comfortable as when switching channels on television.